Manufacturing may be energy-intensive, causing energy to be a large part of the expense of manufacturing products. The cost of energy may vary as a function of time, such as depending on the time of day. There may, for example, be peak-on times and peak-off times, where energy costs more during the peak-on times than during the peak-off times. The cost may also vary depending on the season, such as different costs during the winter than during the summer. The cost of energy may also vary based on total usage, such as a first cost for the first number of kilowatt hours in a time period, and then a second, more expensive, cost per kilowatt hour in the same time period.
Manufacturers may also have deadlines to meet for manufacturing products. Customers may impose penalties for not meeting deadlines. Manufacturers may consider tradeoffs between the penalties for not meeting deadlines and increased production costs for ramping up production during a time when the cost of energy is high. Manufacturers may also have to consider dependencies between manufacturing tasks, by which some tasks must be completed before other tasks.